I've been noticing (especially now that its colder) that my starter just seems to be working really hard to start the truck (05 fx4)

So, i hooked my DMM to the battery at rest and found it to be under 12v, so I said what the hell and bought an optima yellow top...

Now, I chose that battery due to having two high current drawing audio amplifiers.

I install that battery, the initial start on a new battery is usually a little slow, and it was, but it started..

Second time i tried to start with the new battery which was immediately after shutting the truck off after driving 15 miles, the battery was dead!

I know, right now you're thinking ALTERNATOR!!, but im sorry thats not it, my alternator is producing 14.5 volts when the truck is running

So today i took a test light and tested the negative current from the battery for any drain and the test light is dim but it is obviously lit (thats with the main 4 gauge wire for my audio junk disconnected from the battery)

Now if i touch my main audio power wire to the battery the test light does get significantly brighter...

So here are my questions:

- If my 4 guage wire going to my capacitor and (then to my amps) were shorting out on the body somewhere due to a tear in the insulation or a fray somewhere, what is the best way to test for that?

- Should there be enough draw under normal circumstances for the test light to be lit up a little bit like it is?


Thanks!

 

Update: 4 gauge wire is not shorted..

I determined that less draw occurs on the battery when the "keep alive memory for pcm and climate control module" and "cluster keep alive power" fuses are removed.

One of which does provide constant power to the head unit..

Also my capacitor is not staying charged, its down to around 4 volts?

p.s. does anyone know any reputable upgraded output alternators??